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<head><meta charset="utf-8"><title>meeting 2020-12-01 · wg-traits · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/index.html">wg-traits</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html">meeting 2020-12-01</a></h3>

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<a name="218479897"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218479897" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218479897">(Dec 01 2020 at 20:53)</a>:</h4>
<p>Hi <span class="user-group-mention" data-user-group-id="692">@WG-traits</span> <br>
Meeting in 7 minutes</p>



<a name="218480912"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218480912" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218480912">(Dec 01 2020 at 21:00)</a>:</h4>
<p>Hi <span class="user-group-mention" data-user-group-id="692">@WG-traits</span>, meeting time</p>



<a name="218481028"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481028" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481028">(Dec 01 2020 at 21:01)</a>:</h4>
<p>oof shoot! I meant to comment that I got double scheduled</p>



<a name="218481051"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481051" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481051">(Dec 01 2020 at 21:01)</a>:</h4>
<p>Oof</p>



<a name="218481055"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481055" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481055">(Dec 01 2020 at 21:01)</a>:</h4>
<p>Okay</p>



<a name="218481064"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481064" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481064">(Dec 01 2020 at 21:01)</a>:</h4>
<p>I can probably read async a bit</p>



<a name="218481071"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481071" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481071">(Dec 01 2020 at 21:01)</a>:</h4>
<p>but I may be quite distracted</p>



<a name="218481120"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481120" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481120">(Dec 01 2020 at 21:02)</a>:</h4>
<p>Well, I was about to write that we don't have a ton to talk about</p>



<a name="218481130"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481130" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481130">(Dec 01 2020 at 21:02)</a>:</h4>
<p>Except maybe <a href="https://github.com/rust-lang/chalk/issues/658">chalk#658</a></p>



<a name="218481144"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481144" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481144">(Dec 01 2020 at 21:02)</a>:</h4>
<p>And <a href="#narrow/stream/144729-wg-traits/topic/Wellformed.20Placeholder.20Types">https://rust-lang.zulipchat.com/#narrow/stream/144729-wg-traits/topic/Wellformed.20Placeholder.20Types</a></p>



<a name="218481169"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481169" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481169">(Dec 01 2020 at 21:02)</a>:</h4>
<p>As well as the usual updates/announcements</p>



<a name="218481318"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481318" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481318">(Dec 01 2020 at 21:04)</a>:</h4>
<p>So, I guess anyone who has updates can just post them (I'm curious if anyone's done any work)</p>



<a name="218481417"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481417" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481417">(Dec 01 2020 at 21:04)</a>:</h4>
<p>For me, kind of stuck on the rustc binder refactor. But not <em>quite</em> as stuck as I thought I was</p>



<a name="218481482"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481482" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> lcnr <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481482">(Dec 01 2020 at 21:05)</a>:</h4>
<p><a href="https://github.com/rust-lang/rust/issues/79313">#79313</a> might be interesting to some of you <span aria-label="sparkles" class="emoji emoji-2728" role="img" title="sparkles">:sparkles:</span></p>



<a name="218481504"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481504" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481504">(Dec 01 2020 at 21:05)</a>:</h4>
<p>I also did some cleanup in Chalk. It's currently based on <a href="https://github.com/rust-lang/chalk/issues/658">chalk#658</a>, so not yet going to PR</p>



<a name="218481537"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481537" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481537">(Dec 01 2020 at 21:05)</a>:</h4>
<p><span class="user-mention" data-user-id="216206">@lcnr</span> I saw that, but didn't read through it</p>



<a name="218481567"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481567" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Matthew Jasper <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481567">(Dec 01 2020 at 21:05)</a>:</h4>
<p>The rework of WF clauses to not have escaping bound variables is mostly done and is waiting for opinions on the topic in that thread.</p>



<a name="218481694"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481694" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481694">(Dec 01 2020 at 21:06)</a>:</h4>
<p>So <span class="user-mention" data-user-id="116118">@Matthew Jasper</span>, hmm. Let me think</p>



<a name="218481748"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481748" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481748">(Dec 01 2020 at 21:07)</a>:</h4>
<p>I guess, when does this come up?</p>



<a name="218481867"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481867" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Matthew Jasper <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481867">(Dec 01 2020 at 21:08)</a>:</h4>
<p>When we check, say, <code>struct A&lt;T&gt;(T)</code> is well-formed, we check that all field types are well-formed, which means that we need to check that<code>T</code> is well-formed.</p>



<a name="218481933"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481933" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481933">(Dec 01 2020 at 21:08)</a>:</h4>
<p>Right, so. I would expect that <code>WellFormed(T)</code> would be in the environment</p>



<a name="218481969"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218481969" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Matthew Jasper <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218481969">(Dec 01 2020 at 21:09)</a>:</h4>
<p>Yes, but currently it's not.</p>



<a name="218482030"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218482030" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Matthew Jasper <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218482030">(Dec 01 2020 at 21:09)</a>:</h4>
<p>I can add it to all environments if we think that makes sense.</p>



<a name="218482134"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218482134" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218482134">(Dec 01 2020 at 21:10)</a>:</h4>
<p>Yeah, I don't know if it makes sense to have it in the environment, or to say that all placeholders are WF</p>



<a name="218482146"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218482146" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> lcnr <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218482146">(Dec 01 2020 at 21:10)</a>:</h4>
<p>(I personally feel like <code>WF(param/placeholder)</code> should be trivially true but don't know how you handle this in chalk so it may not necessarily make sense)</p>



<a name="218482430"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218482430" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218482430">(Dec 01 2020 at 21:13)</a>:</h4>
<p>In rustc, WF(placeholder) is always true right?</p>



<a name="218482442"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218482442" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Matthew Jasper <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218482442">(Dec 01 2020 at 21:13)</a>:</h4>
<p>Yes</p>



<a name="218482560"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218482560" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218482560">(Dec 01 2020 at 21:14)</a>:</h4>
<p>Then I think it's fine to just make them WF in Chalk</p>



<a name="218482603"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218482603" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218482603">(Dec 01 2020 at 21:14)</a>:</h4>
<p>I think I've run into this before, when I was originally adding the Chalk integration into rustc, but I don't remember the resolution</p>



<a name="218482701"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218482701" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218482701">(Dec 01 2020 at 21:15)</a>:</h4>
<p>But this has been around since before I started working on Chalk, so maybe there's something related to implied bound here</p>



<a name="218483143"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218483143" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218483143">(Dec 01 2020 at 21:19)</a>:</h4>
<p>I'm looking now at how WF goals for structs are created in Chalk</p>



<a name="218483210"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218483210" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218483210">(Dec 01 2020 at 21:20)</a>:</h4>
<p>But I can't find it...</p>



<a name="218483241"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218483241" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218483241">(Dec 01 2020 at 21:20)</a>:</h4>
<p>oh, it's <code>verify_adt_decl</code></p>



<a name="218483324"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218483324" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218483324">(Dec 01 2020 at 21:21)</a>:</h4>
<p><span class="user-mention" data-user-id="116118">@Matthew Jasper</span> so is this just coming from the rustc integration?</p>



<a name="218483356"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218483356" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218483356">(Dec 01 2020 at 21:21)</a>:</h4>
<p>Or are you running into it with the integration tests</p>



<a name="218483644"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218483644" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Matthew Jasper <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218483644">(Dec 01 2020 at 21:24)</a>:</h4>
<p>I'm running into it with the integration tests.</p>



<a name="218484239"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/meeting%202020-12-01/near/218484239" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jack Huey <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/meeting.202020-12-01.html#218484239">(Dec 01 2020 at 21:28)</a>:</h4>
<p>uh, interesting</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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